What Is A Good, Powerful Vacuum To Buy? What Is The Cost On It?

Our vacuum cleaner doesn’t work anymore and we looking at some at Wal Mart, and I can’t decide….. We recently were a little surprised by an in-home sales demo on a Kirby vacuum cleaner. It was an unexpected visit, and it was no surprise how much dirt and hair got pulled up out of the 10 feet of carpet the guy vaccumed. We were shocked at the astronimical price of $1995.00 for the stupid thing, and even more shocked when the sales rep “negotiated” the price down to a mere $700.
Anyway, we didn’t buy it, and sent the guy packing. I’m not paying that much for a vacuum. But, it did work – and it worked well.
We have a 1 dog, 3 cats, and 3 ferrets, in addition to a bird, and horse barn-dirt that contributes to what ends up in our carpet, so I would like something as powerful of a cleaner (or close to) without the unreal price tag of a Kirby.
Some of the vaccuums by hoover at wal mart were around $200 – what would be a good vacuum for my needs??